Apparatus and methods for transferring blood between aspiration assembly and an external container

ABSTRACT

An aspirator receiver forms part of a blood aspiration system for injecting fluid into a patient and withdrawing undiluted blood. The aspirator receiver has a housing with a passage occluded by a septum and in communication with the blood flow channel through the aspirator system. An aspirator comprises a cannula having a blunt tip surrounded by a shroud, the cannula being in communication with a blood receiving receptacle. The aspirator is applied to the housing with the shroud centering the cannula about and for penetration through the septum of the housing whereby undiluted blood may be withdrawn from the flow channel into the receptacle. Upon removal of the aspirator, the septum occluding the end of a standard vacuum-filled container is penetrated by the cannula whereby blood from the receptacle may be transferred into the container. The housing and container septa are of like external configuration and dimension and the shroud is complementary in dimension to facilitate transfer of the blood from the aspirator system to the receptacle and finally to the container.

This is a continuation of application Ser. No. 07/760,468, filed onSept. 17, 1991 which was abandoned upon the filing hereof which was acontinuation-in-part of Ser. No. 7/594,677 filed Oct. 10, 1990; now U.SPat. No. 5,178,607 which was a continuation Ser. No. of 07/302,835 filedJan. 27, 1989, abandoned which was a continuation-in-part of 07/080,406filed Jul. 31, 1987; now U.S. Pat. No. 4,838,855 which was acontinuation-in-part of Ser. No. 07/540,605 filed Jun. 19, 1990 now U.S.Pat. No. 5,164,400.

BACKGROUND AND SUMMARY OF THE INVENTION

In the above-noted U.S. Pat. No. 4,838,855 by one of the co-inventorshereof, there is disclosed an aspiration system for supplying fluid toand withdrawing undiluted blood from tubing connected to the bloodvessel of a patient, for example, by an in-dwelling catheter, withoutopening the tubing system to atmosphere. In that system, a proximalsection of tubing is placed in communication with a source of fluidunder pressure, for example, intravenous fluid. The proximal tubingsection extends to a two-way valve, which in turn is connected to anintermediate tubing section. The intermediate tubing section isconnected to an aspirator receiver, in turn connected to distal tubingcoupled to the in-dwelling catheter. In one position of the valve, theintermediate tubing section is connected with a fluid reservoir and inthe other position of the valve, the intermediate tubing section iscoupled with the source of fluid under pressure. The aspirator receiverincludes a housing having a flow channel and a passage in communicationwith the flow channel and occluded by a septum. The septum is formed ofresilient material such that a needle may penetrate the septum towithdraw blood from the flow channel and, upon withdrawal of the needle,the septum is self-sealing.

In that system, the fluid reservoir has a volume sufficient such that,when the valve is opened to afford communication between the reservoirand the intermediate and distal tubing sections and is closed to thesource of fluid under pressure, sufficient resident fluid in thosetubing sections can be withdrawn into the reservoir so that theaspirator receiver is filled with undiluted blood from the in-dwellingcatheter through the distal tubing into the aspirator receiver flowchannel. When the reservoir is full, a needle forming part of a syringe,may be inserted through the septum of the aspirator receiver and intocommunication with the blood in the flow channel. The undiluted bloodunder pressure thus fills the syringe. Once a satisfactory sample hasbeen obtained, the syringe needle may be withdrawn from the aspiratorreceiver septum which automatically reseals. Pressure is then applied tothe fluid temporarily resident in the reservoir to return such fluid tothe tubing sections without loss of blood other than that actuallyremoved for testing. Indeed, measurements can be made without any lossof blood by interfacing the blood analysis section directly with bloodanalysis sensors or membranes.

In our prior U.S. Pat. No. 5,178,607, there are also disclosed certainimprovements in the above-described system, including a blunt cannula orneedle for use with a preperforated septum. As explained in thatapplication, the use of a blunt cannula or needle prevents accidentalneedlesticks typically associated with inserting a needle through septaor, more generally, when using unprotected needles. The blunt needle isthus used in connection with a preperforated septum which is alsoself-sealing. The tip of the blunt needle enables the force required topass the tip of the blunt needle into the septum to be considerably lessthan the force required to penetrate the surface of normal intact humanskin of the hand or arms whereby accidental misdirection of the bluntneedle tip against the skin will not result in penetration of the skin.Hence, the risk of needlestick while obtaining blood sample through theseptum is virtually eliminated.

In our U.S. Pat. No. 5,114,400 an improvement with respect to the twosystems previously described is disclosed which eliminates the problemof blood spurting from the cannula tip when the cannula is removed fromthe septum of the aspirator receiver. The syringe typically has a bubbleof air trapped within its interior chamber. The elevated pressure withinthe flow channel when the cannula is inserted through the septumpositively pressurizes the syringe during sampling, compressing that airbubble. Upon removal of the cannula, the opening at the tip of thecannula is exposed to the lower atmospheric pressure, thus causing thepressurized air bubble within the syringe to expand and the blood toundesirably spurt from the tip of the cannula.

In U.S. Pat. No. 5,114,400 that blood spurting problem is cured byenabling depressurization of the air bubble within the syringe while thecannula tip is occluded from fluid communication with the pressurizedblood vessel. Although other means to occlude such fluid communicationare included in the teaching, the preferred embodiment discloses the useof the septum to occlude the cannula near its tip. Particularly, ashroud is provided about the blunt cannula which, in cooperation withthe aspirator receiver housing, indicates when the tip of the cannula isoccluded within the septum during withdrawal of the cannula from theseptum. Such occlusion indicator preferably includes cooperating detentson the aspirator receiver housing and the shroud affording sensoryperception of the occlusion. When those detents engage, the sensory,e.g., tactile indication afforded thereby, permits the nurse totemporarily stop withdrawing the cannula from the aspirator receiverhousing and to retract the syringe piston. This induces a negativepressure in the syringe barrel, enabling expansion of the trapped airbubble within the syringe. Upon full withdrawal of the cannula, theatmospheric pressure is at least equal to or greater than the pressurewithin the syringe thus eliminating the blood spurting problem.

Notwithstanding these various improvements in blood aspirationassemblies, there remains a significant problem in transferring theblood sample from the aforementioned syringe to another container, forexample, the standard adult vacuum-filled container. A container of thistype typically comprises a cylindrical glass or plastic tube closed atone end. Its opposite open end is normally occluded by a septum, i.e., arubber stopper. Typically, a practitioner would penetrate the septum ofthe aspirator receiver with the needle of a conventional syringe,withdraw the needle once an adequate volume of blood had been withdrawninto the syringe, and then attempt to direct the needle tip forpenetration through the septum of the vacuum container. Obviously, usingthat procedure, there is substantial danger of accidental needlestickduring insertion of the needle of the syringe into the septum of theaspirator receiver, its withdrawal from that septum, movement of thesyringe to the vacuum container, and attempted penetration of the rubberseptum of the container.

This problem has been recognized and a very complex solution to theproblem has been offered. Particularly, a blood protection system hasbeen developed which is illustrated in FIGS. 10 and 11 hereof. Thatsystem includes a sampling syringe S (FIG. 6) having a shrouded cannulaC. The shrouded cannula is applied to the septum of an aspiratorreceiver R of an aspiration system AS to withdraw a blood sample. Thecannula C is then removed from the aspirator receiver housing. Thecannula, however, is too blunt to penetrate the septum 146, usuallyformed of rubber or like material, of the vacuum-filled container 148 toeffect direct transfer of the blood sample to the container. Moreover,the shroud about the cannula does not match the septum on the standardadult vacuum-filled container C (FIG. 11). This system thus employs anintermediate blood transfer unit BTU which includes a bore at one endoccluded by a septum 150 penetrable by the shrouded blunt cannula C. Atthe opposite end, there is provided an elongated cylindrical chamber 152open at one end for receiving the vacuum-filled container C, septum endfirst. The container is advanced within this chamber such that a needle154 forming part of the blood transfer unit may penetrate the septum ofthe vacuum container 148. The needle 154 is in communication with thebore at the opposite end of the blood transfer unit. When the container148 and sampling syringe S are connected to the blood transfer unit,blood is then transferred from the sampling syringe S through its bluntcannula C, and through the septum 150 and bore at one end of the bloodtransfer unit BTU and then through the needle 154 of the blood transferunit through the septum of the vacuum container for reception within thecontainer. Direct transfer of blood from the sampling syringe S to thecontainer 148 in that system is not possible because the blunt cannula Cis not sufficiently sharp to penetrate the septum 146 of thevacuum-filled container 148. Also, the shroud 156 of the samplingsyringe is too small to accommodate the septum of the vacuum-filledcontainer.

According to the present invention, there is provided apparatus andmethods for transferring blood between the aspirator receiver of a bloodaspiration system and a standard adult vacuum-filled container whichminimizes problems associated with needlesticks and consequenttransmittal of infectious diseases and the need for any intermediateblood transfer unit. In accordance with the present invention, there isprovided an aspirator having at one end a cannula extending within, butradially spaced from, a surrounding shroud. The tip of the cannula isblunt yet sufficiently sharp to penetrate the septum of a standardvacuum-filled container. Direct transfer of the blood sample from theaspirator to the vacuum container is accomplished by (i) forming theseptum of the aspirator receiver housing (including any surroundingportion of the housing) substantially identical in shape and dimensionto the septum of the standard adult vacuum-filled container; and (ii)forming the interior of the shroud complementary to both the septum ofthe aspirator receiver housing (including any surrounding portion of thehousing) and the septum of the standard adult vacuum-filled container.Further, the shroud extends distally beyond the tip of the cannula.While thus recessed from the end of the shroud, the cannula is exposedto engagement by an individual's finger inserted within the open end ofthe shroud because the interior diameter required to receive an adultvacutainer is larger than the adult human finger. The tip of the cannulais therefore formed sufficiently blunt to prevent penetration of intacthuman skin on an individual's hands and arms even upon application ofcasual inadvertent force.

To facilitate the transfer of the blood sample from the aspirationsystem to the vacuum-filled container, the aspirator includes aninterior chamber or receptacle in communication with the bore of thecannula for receiving blood from the flow channel of the aspiratorreceiver through the cannula. The interior chamber can include a plungerfor displacing the blood sample into the vacuum-filled container whenthe aspirator and container are connected.

Preferably, the end of the aspirator receiver housing having the passageoccluded by the septum is substantially identical in shape and dimensionto the end of the vacuum-filled container including its septum.Particularly, the aspirator receiver housing and vacuum-filled containerends are preferably cylindrical, similar or identical in diameter andcomplementary in diameter to the internal diameter of the preferablycylindrically-shaped shroud surrounding the cannula. In this manner, theaspirator may be centered over the septum of the aspirator receiverhousing by engagement of the shroud about the housing end or septum toenable substantial coaxial penetration of the septum, preferably througha perforation in the septum. Penetration may therefore proceed withoutdanger of breaking the cannula by canting it relative to the housing.Upon receipt of the blood sample within its interior chamber, theaspirator may be withdrawn from the aspirator receiver housing,preferably using the aspirator occlusion indicator of the previouslymentioned application, to avoid the problem of blood spurting from thecannula tip upon complete removal of the aspirator. Once removed, theaspirator may be similarly centered upon the stopper of thevacuum-filled container by engagement of the shroud about the stopper.The blunt cannula is sufficiently sharp to penetrate the stopper of thevacuum-filled container without preperforating the septum. The plungerof the aspirator may then be actuated to facilitate displacement of theblood sample from the aspirator directly into the container. Uponseparation of the aspirator and container, the stopper of thevacuum-filled container automatically seals.

In a preferred embodiment according to the present invention, there isprovided, in combination with a blood aspiration system connected to apressure transducer and a discrete container, an apparatus fortransferring a sample of blood from the aspiration system to thediscrete container comprising an aspirator including an axiallyextending cannula having a distal tip, the cannula having a bore withfirst and second openings adjacent opposite ends of the bore and ashroud extending about the cannula in transversely spaced relationthereto, the shroud extending axially beyond the distal tip of thecannula, an aspiration receiver which forms part of the blood aspirationsystem and which includes a housing having a flow channel forcommunication with the human vasculature for flowing blood through theflow channel, the housing having a portion for receiving the cannula tolocate the first opening of the cannula in communication with the flowchannel. Blood receiving means are coupled to the aspirator incommunication with the second opening for receiving blood. The discretecontainer has an opening at one end and a stopper occluding the opening,the external configurations of the one end of the container and thehousing receiving portion, respectively, being complementary to theinternal configuration of the shroud whereby, (i) upon application ofthe aspirator to the aspirator receiver, the shroud engages about thehousing receiving portion and centers the cannula for penetration of thehousing receiving portion to locate the first opening in communicationwith the flow channel and thereby to communicate blood from the flowchannel through the bore into the blood receiving means, and, (ii) uponremoval of the aspirator from the aspirator receiver and uponapplication of the aspirator to the container, the shroud engages aboutthe container end and centers the cannula for penetration through theseptum of the container to locate the first opening in communicationwith the container and thereby to communicate blood from the receivingmeans through the bore into the container.

In a further preferred embodiment according to the present invention,there is provided apparatus for transferring a sample of blood from aflow channel in fluid communication with an aspirator receiver to adiscrete container closed at one end by a stopper, the flow channelbeing adapted for communication with the lumen of a blood vessel of apatient and a passage of the aspirator receiver opening through anaspirator receiver portion having a predetermined outside diameter andwhich passage is occluded by a septum, comprising an aspirator includingan axially extending cannula having a distal tip, a first openingadjacent the tip for receiving blood from the flow channel uponpenetration of the septum by the cannula, a second opening and a borethrough the cannula extending between the first and second openings, thecannula being adapted for connection to a receptacle for communicatingblood received through the first opening into the bore and through thesecond opening into the receptacle and a generally cylindrical shroudextending about the cannula in radially spaced relation thereto andextending distally axially beyond the distal tip of the cannula, theinternal diameter of the shroud being at least as great as about 17.5 mmfor successively receiving the aspirator receiver portion and the endsof the container enabling transfer of blood directly from the aspiratorreceiver to the receptacle and from the receptacle directly through thecannula to the container.

In a further preferred embodiment according to the present invention,there is provided a method of transferring a sample of blood from a flowchannel in an aspirator receiver of an aspiration system to a discretecontainer having a septum closing one end thereof wherein the flowchannel is adapted for communication with the lumen of a blood vessel ofa patient and the aspirator receiver has a housing portion for receivinga cannula, comprising the steps of providing a flow of blood from thepatient into the flow channel, positively centering the cannula of theaspirator relative to the housing receiving portion by engaging a shroudon the aspirator about the housing receiving portion, penetrating thehousing receiving portion with the centered cannula to place the cannulain communication with the blood in the flow channel, flowing blood fromthe flow channel through the cannula for reception in a receptacle incommunication with the cannula, removing the aspirator from theaspirator receiver, positively centering the cannula relative to theseptum of the container by engaging the shroud of the aspirator aboutthe end of the container, penetrating the septum of the container withthe centered cannula to place the container in communication with theblood in the receptacle and flowing blood from the receptacle into thecontainer.

It is therefore a primary object of the present invention to provideapparatus and methods for the direct transfer of a blood sample from ablood aspirator assembly to an adult vacuum-filled container withoutinjury from needlesticks, in a manner achieving a centering of thecannula relative to the septa thereby avoiding breaking the cannula, andwithout the need for any intermediate blood transfer unit.

These and further objects and advantages of the present invention willbecome more apparent upon reference to the following specification,appended claims and drawings.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIG. 1 is a fragmentary schematic illustration with portions in crosssection of a blood aspiration system employing apparatus and methods fortransferring blood from the system to an external container according tothe present invention;

FIG. 2 is a side elevational view with parts broken out and incross-section illustrating a portion of the aspiration system includingthe blood transfer apparatus according to the present invention;

FIG. 3 is an enlarged fragmentary cross-sectional view illustrating theblood transfer apparatus hereof connected to the septum of an aspiratorreceiver of the aspiration system;

FIG. 4 is an enlarged view similar to FIG. 3 illustrating the bloodtransfer apparatus hereof poised for centering on the septum of an adultvacuum-filled container;

FIG. 5 is a view similar to FIG. 4 illustrating the blood transferapparatus applied to the container in position to transfer blood fromthe blood transfer apparatus to the container;

FIGS. 6 and 8 are fragmentary side elevational views of the tips ofrespective embodiments of two cannulas forming part of the presentinvention;

FIGS. 7 and 9 are cross-sectional views thereof taken generally about onlines 7--7 and 9--9 of FIGS. 6 and 8, respectively;

FIG. 10 is a perspective view of a portion of a prior art blood transferapparatus illustrated as applied to an aspiration system; and

FIG. 11 is a perspective view of the complete prior art blood transferapparatus of FIG. 10 illustrating the successive transfer of blood froma syringe to a blood transfer unit and then to a vacuum-filledcontainer.

DETAILED DESCRIPTION OF THE DRAWING FIGURES

Reference will now be made in detail to a present preferred embodimentof the invention, an example of which is illustrated in the accompanyingdrawings.

Referring now to the drawings, particularly to FIG. 1, there isillustrated a blood aspiration system of the type disclosed in our priorco-pending application Ser. No. 07/302,835, filed Jan. 27, 1989, nowabandoned and which includes tubing, generally indicated 10, havingproximal and distal end tubing sections 11 and 24, respectively. A fluidsource 15 under pressure, for example, an intravenous fluid-filledpressure bag, is in communication with proximal tubing section 11.Tubing section 11 is connected to a conventional coupling 17 for aconventional trigger squeeze one-way valve mechanism 19. The distal endof valve mechanism 19 is coupled to a pressure transducer 20, in turnconnected to a two-way valve 21. Pressure transducer 20 is per seconventional and is typically used to monitor blood pressure. Valve 21is coupled to an intermediate tubing section 23, for purposes describedhereinafter. Valve 21 has a port in communication with a fluid reservoir25 having a manually-operated piston 27. Valve 21 may be manuallyoperated to provide (i) communication between fluid source 15 andintermediate tube 23 through tubing section 11, thereby preventingcommunication between tubing 10 and reservoir 25; or (ii) communicationbetween tubing section 23 and reservoir 25, thereby preventingcommunication between reservoir 25 and tubing section 11 with the fluidsource 15.

Tubing section 23 preferably comprises a generally larger diameter tubethan tubing 24 for reasons discussed hereinafter, and has its distal endcoupled to a blood aspirator receiver 30 forming part of the presentinvention. Blood aspirator receiver 30 is in turn coupled to tubingsection 24 connected to a catheter 14.

From a review of the foregoing description and prior application Ser.No. 07/302,835, now abandoned it will be appreciated that intravenousfluid from fluid source 15 fills tubing 10 and the various elementsbetween the source and the catheter excluding reservoir 25 whereby fluidis administered to the patient. To withdraw a blood sample from thepatient, valve 21 is manipulated to place reservoir 25 in communicationwith the tubing 23 and, hence, the vasculature system of the patientthrough distal tubing end section 24 and catheter 14. By withdrawingpiston 27 of reservoir 25, a predesignated volume of fluid resident intubing sections 23 and 24 is withdrawn into reservoir 25. This enables afluid volume to be withdrawn into the enlarged tubing section 23 whichis not sufficient to permit blood from the patient's vasculature toenter reservoir 25, but sufficient to provide blood in the aspiratorreceiver 30 which is substantially undiluted by the resident intravenousfluid. The fluid connection between the aspirator receiver 30 and thereservoir 25 is then occluded. A blood sample is then withdrawn from theaspirator receiver housing 30 by penetrating its septum with the bluntcannula of an aspirator to be described. The blood sample is thentransferred from the aspirator of the blood transfer apparatus hereof tothe container. After a blood sample is taken, the fluid communicationbetween the aspirator receiver 30 and the reservoir 25 is reopened andthe piston 27 in reservoir 25 is advanced to discharge the fluidtemporarily stored therein into the tubing to return blood within thetubing to the patient. Once reservoir 25 is emptied, valve 21 is rotatedto provide communication between fluid source 15 and catheter 14 wherebyintravenous fluids can be further administered to the patient and toflush any residual blood from the system.

Referring to the form of the aspirator receiver 30 illustrated in FIG.3, aspirator receiver 30 includes a housing 34 having a flow channel 50and a passage 38 in communication with flow channel 50. Passage 38 isoccluded by an elongated elastomeric septum 40 which extends from a flowchannel interface 44 to an atmospheric interface 48. A centralperforation extends from the atmospheric interface 48 of septum 40 tothe flow channel interface 44. The outer surface 52 of housing 34preferably has an annular housing detent 54. Housing 34 may be formed ofa rigid plastic material or may be formed of an elastomeric materialharder than the elastomeric material of septum 40 or may itself compriseseptum 40. Alternative embodiments of septa are also disclosed in ourprior application Ser. No. 07/302,835, now abandoned.

The blood transfer apparatus hereof further includes an aspirator 68 anda receptacle for receiving the blood sample withdrawn from flow passage50. The receptacle may comprise the barrel of a conventional syringe 60.Syringe 60 includes a syringe tip 62 which lies in communication withthe bore 63 of an elongated hub 68. Adjacent the distal end of hub 68,there is provided a cannula 58 having a bore 69 in communication withthe bore 63 of hub 68. Cannula 58 terminates in a blunt tip 78,described in detail hereafter, having a side opening 74 which, when theaspirator is applied to the aspirator receiver 30 lies in communicationwith flow channel 50. Thus, a flow passage is established between flowchannel 50 and the receptacle or the barrel of syringe 60 through thecommunicating bores 69, 63 and 62. A piston or plunger 70 is mountedwithin the receptacle or barrel of syringe 60.

Preferably forming an integral part of the aspirator is a shroud 80,which includes a base 81 extending radially outwardly from and adjacentone end of cannula 58. Shroud 80 also includes an enclosure, preferablya generally-cylindrical skirt 82, depending from base 81. The internalsurface 86 of skirt 82 is complementary to the outer surface ofaspirator receiver housing 34. Particularly, the internal configurationand dimension of shroud 80, defined by the internal surface 86 of skirt82, is substantially complementary and equal to the externalconfiguration and dimension of the outer surface 52 of the aspiratorreceiver housing 34. The spacing between housing 34 and skirt 82 isexaggerated in FIG. 3 to illustrate the detenting action forming part ofthe aspirator occlusion indicator described below. The distal end ofshroud 80 also terminates in an inwardly extending detent 90 (FIGS. 4and 5).

When employing the aspirator, the shroud is initially centered uponaspirator receiver housing 34, thereby centering the tip 78 of cannula58 in the preperforated septum 40. By displacing the aspirator axiallytoward the aspirator housing, shroud detent 90 is pushed past housingdetent 54 as the cannula tip is advanced through the preperforatedseptum 40. Upon full penetration, the cannula tip lies within flowchannel 50 enabling a blood sample to be withdrawn through cannula tipopening 74 and bores 69, 63 and 62 into the barrel of the syringe. Inthe final position of assembly of the aspirator on the aspiratorreceiver housing, note that detents 54 and 90 are spaced axially onefrom the other. When sampling is completed, the aspirator is withdrawnaxially from the aspirator receiver housing. However, during withdrawal,shroud detent 90 engages housing detent 54 to provide a tactileindication that the cannula tip opening 74 is occluded by theelastomeric septum 40. At that point, the chamber 79 of the receptacleor syringe barrel is completely sealed so that withdrawal of piston 70cannot draw air or additional blood into the receptacle or syringe 60,but rather, will eliminate any positive pressure within chamber 79. Thatis, any air bubble extant in chamber 79, upon slight withdrawal of thepiston of the syringe, will obtain atmospheric or negative pressurerather than its previous positive pressure. Thus, upon furtherwithdrawal of the aspirator from the aspirator receiver housing, i.e.,the cannula 58 from septum 40, the air entrapped within the syringebarrel, being at a pressure equal to or lower than atmospheric pressure,will preclude blood from spurting from the cannula tip upon its removalfrom the aspirator receiver housing. It will be appreciated that othertypes of sensory indications may be provided for indicating when thecannula tip is sealed. For example, gradations on the housing, coloredor clear, or bayonet type joints between the aspirator and housing maybe employed.

Once the aspirator has been removed from the aspirator receiver housing,it is applied and connected directly to a standard adult vacuum-filledcontainer to transfer the blood sample from the chamber 79 into thecontainer. With reference to FIGS. 4 and 5, a standard adultvacuum-filled container 92 comprises a cylindrical, typically glass orplastic, housing 94 closed at one end and open at its opposite end. Theopen end is normally occluded by a septum 96, e.g., a rubber stopper.Septum 96 has a neck portion 98 received in the open end of container 94and a radially outwardly directed flange 100 overlying the end ofcontainer 92, the outer face of septum 96 being conventionally recessedat 102. Septum 96 is not preperforated and the rubber material formingseptum 96 must be slit or perforated by the cannula 58 of the bloodtransfer apparatus in order to locate cannula tip 78 within container 94and tip opening 74 in communication with the container, as illustratedin FIG. 5. The dimensions and forces necessary to accomplish this areset forth below in terms of the bluntness of the needle and the forcerequired to penetrate the septum.

In accordance with the present invention, the internal surface 86 ofshroud 80 is complementary to the external surface about the septum 96of the container 92. Particularly, the internal configuration anddimension of shroud 80 is substantially complementary to the externaldiameter dimension and configuration of the septum 96. Thus, the shroudis complementary to both the aspirator receiver housing and the septumof the container.

To transfer the blood sample into container 92, the aspirator andcontainer are aligned such that shroud 80 is in substantial axialalignment with septum 96. By forming shroud 80 complementary to septum96, particularly the flange 100 of the septum 96, shroud 80 and, hencecannula 58, may be centered with respect to septum 96. Thus, when theaspirator and septum of the container are connected, the septum isreceived within the shroud with the shroud centering and coaxiallyaligning the cannula relative to the septum and the container. That is,a substantially coaxial relation is obtained between the container andthe cannula such that by engaging the shroud and septum, the cannulacannot substantially cant or incline upon application of the forcenecessary for the cannula to penetrate the septum. This prevents thecannula from being broken or fractured upon penetration through theseptum.

To effect transfer of the blood sample from the aspirator directly tothe adult vacuum-filled container in accordance with the presentinvention the external configurations of the aspirator receiver housingand the occluded end of the vacuum-filled container are substantiallyidentical in configuration and dimension relative to one another andcomplementary to the internal configuration and dimension of the shroud.Preferably, these configurations are generally cylindrical and thereforethe diameters of the aspirator receiver housing and the septum of thevacuum-filled container are substantially equal enabling these elementsto form a relatively close or tight fit with the shroud, whose internaldiameter is therefore only slightly larger. By applying an axial forceto the aspirator, the cannula penetrates through septum 96 of thevacuum-filled container until the base of the shroud engages the outersurface of the septum. At that time, opening 74 at the distal end of thecannula is located beyond the septum and within the container. Thepiston of the syringe may then be advanced to displace the blood samplefrom the syringe into the container. When the container is filledsufficiently, the cannula is withdrawn and the elastomeric material theseptum 96 seals the opening.

In the preferred form hereof, the septum or stopper 96 is generallycylindrical and has a diameter of about 16 mm. The internal diameter ofthe shroud is about 17.5 mm. The diameter of the aspirator receiverhousing portion which receives the shroud and includes the septumreceiving cannula has an outer diameter of about 17.5 mm. The length ofthe aspirator receiver housing from the face of its septum to the bottomof the housing is 18 mm. With respect to septa 40 or 96, each septum perse may extend to the full diameter indicated or be surrounded by anotherpart or housing which has that diameter of. It is significant, however,that the diameters of the septa be substantially equal to one anotherand that the internal diameter of the shroud be sufficiently large toaccommodate both septa. It will also be appreciated that there is asmall population of vacuum-filled containers having septa with diameterssmaller than noted above. These likewise may be used with the directblood transfer apparatus hereof as they too are sized for receptionwithin the shroud.

In accordance with another aspect of the present invention, cannula 58has a blunt tip sufficiently sharp to penetrate the otherwiseunpenetrated, unperforated septum of the vacuum-filled container yet notsufficiently sharp with casual force to penetrate an individual's skinwhereby the problem of inadvertent needlestick is greatly reduced. Itwill be appreciated that because the aspirator receiver housing andseptum of the vacuum-filled container have substantial diameters, andnotwithstanding that the shroud extends axially beyond the distal tip ofthe cannula, there is a sufficient opening at the distal end of theshroud for the finger of an individual to touch the tip of the cannula,hence, the potential for a needlestick injury. To prevent that, as wellas to afford the cannula sufficient sharpness to penetrate the closedseptum of the vacuum-filled container, the blunt tip of the cannula isformed particularly to achieve those objectives.

Referring to FIGS. 6 and 7, cannula 58 has a rounded tip 100. The radiusof curvature of tip 100 is about 0.25 mm, for use with the perforatedseptum 40. With particular reference to FIG. 7, one side 102 of cannula58a near tip 100 is recessed at 102.

The hub 68 of the aspirator has a longitudinal bore 63 of low internalvolume which is in open communication with bore 69 of cannula 58a. Bore69 tapers from a larger diameter to a smaller diameter as it extendsdistally. Near the distal end of cannula 58a, bore 69 angles atapproximately 20° toward the recessed side 102 and has the opening 74through side 102. To the proximal side of opening 74, cannula 58a has asmooth slanted edge 104.

Beyond the rounded tip 100, as the cannula 58a extends proximally, itcan flare out into a conical section 106 having an angle of about 30° ,as shown in FIG. 7. Thence, the needle extends into a conical section108 having a smaller angle than 30° , such as an angle of about 20° ,also as shown on the right of FIG. 7.

With a form of septum 40 of the type described in FIGS. 18-20 of our,co-pending application Ser. No.07/302,835, now abandoned to achievetotal penetration of septum 40 by a polycarbonate cannula 58a havingdimensions heretofore described to position the tip 100 within the flowchannel 50, as illustrated in FIG. 3, the aspirator can be applied toand inserted into the septum by a force of about 4.1 pounds (1.824×10⁶dynes) applied perpendicular to the surface of the septum. Additionally,the force required for the aspirator to penetrate the stopper of aconventional vacutainer is about 5.4 pounds (2.402×10⁶ dynes). As known,a sharp 20-gauge steel needle of the type conventionally used in theprior art results in penetration of the skin of the dorsum of the handwith a force of about 0.12 pounds (53,376 dynes).

A cannula 58 having a tip with a radius of curvature of 0.20 mm to about1 mm can also be used with the septa previously described.

FIGS. 8 and 9 show a modified cannula 58b having a modified tip 110. Theend 112 of tip 110 is flat, and, in an embodiment, can have a diameterof 1.0 mm. The tip angle at 114 can be about 15° and can extendproximally into a section 116 having a smaller angle of about 10° , asseen viewing FIG. 9 toward the right side. The flat end surface 112 canhave an area of 0.78 square mm which can be of circular shape. One sideof the distal end of cannula 58b is recessed at 118 and has an opening120 extending therethrough in flow communication with bore 69.

While the foregoing specifically notes the application of the aspiratorto a standard size adult vacutainer, it will be appreciated that thepresent invention also embraces other sizes of vacutainers. For example,pediatric vacutainers of smaller dimensions, e.g., diameter, arefrequently employed with blood transfer apparatus. In those situations,the aspirator receiver is sized complementary to the aspirator and theaspirator is similarly sized complementary to the pediatric vacutainer.

In contrast with the aforementioned easy penetration of the skinachieved by the typical steel needle, cannula 58b with tip 110 of FIGS.8 and 9 fails to penetrate the skin of the dorsum of the hand whendirected against it at a force of 2.3 pounds (1,023,040 dynes). Hence,it too is much less likely than the conventional steel needle topenetrate the human skin accidentally when the cannula 58b contacts theskin through casual contact.

In summary, the present invention provides a balance between thenecessity of providing a cannula having a tip sufficiently blunt toavoid accidental needlestick injury upon application of the finger tothe tip of the needle with casual force and sufficiently sharp to affordpenetration of the standard septum of a vacutainer. This balance of thedegree of bluntness of the tip of the cannula is necessary because theshroud about the cannula must be sufficiently large to receive the endof the vacutainer carrying the septum, which also means that the shroudis sufficiently large to receive the end of a human finger.

Tests have demonstrated that the force required to insert into andextract the cannula from the septum constructed as previously describedare as follows:

Insertion Force--4.1 pounds or 1.824×10⁶ dynes

Extraction Force--7.5 pounds or 3.336×10⁶ dynes

Tests have also demonstrated that the required force necessary topenetrate the stopper or septum of a vacutainer with the aforedescribedcannula is as follows:

Penetration Force--5.4 pounds or 2.402×10⁶ dynes

Additionally, the shroud centers the cannula about the septum andstopper facilitating insertion and substantially prevents the cannulafrom canting or tilting relative to the septum and stopper, precludingor minimizing the potential for breaking of the cannula.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is to be understood that the invention is not to be limited to thedisclosed embodiment, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. A blood collection system comprising, incombination:a receiver device including a housing having a flow channelfor communication with the human vasculature for flowing blood throughthe housing, a penetrating portion, and a centering portion defined insurrounding relation to said penetrating portion, said centering portionhaving a predetermined external configuration; a discrete, rigid vacuumfilled container having an opening at one end and a septum occluding theopening, said end of said discrete rigid container having apredetermined external configuration; and an apparatus for obtaining asample of blood from said receiver device and for transferring thesample of blood to said discrete, rigid container, the apparatusincluding:an adapter including an axially extending cannula having ablunt distal tip, a first opening adjacent said tip for receiving bloodfrom the flow channel of the receiver device upon insertion of saidcannula into said penetrating portion, a second opening, and a borethrough said cannula extending between said first and second openings;receptacle means coupled to said adapter and including means forinducing a negative pressure within said cannula bore; and a shroudextending about said cannula in transversely spaced relation thereto, atleast a substantial portion of said shroud extending axially beyond thedistal tip of said cannula, said shroud having a predetermined internalconfiguration; said shroud having a maximum transverse, internaldimension at least as great as but not substantially greater than amaximum transverse, external dimension of said end of said container,for successively receiving the centering portion of the receiver deviceand then the end of the container thereby to allow transfer of blooddirectly from the receiver device through the cannula to the receptaclemeans and from the receptacle means directly through said cannula to thecontainer.
 2. Apparatus according to claim 1 wherein said shroud isgenerally cylindrical, has an open distal end, and has an internalcylindrical diameter and an axial extent sufficient to enable an adultfingertip to be inserted within the shroud into contact with the tip ofsaid cannula, said cannula tip being sufficiently blunt to inhibitpenetration of the skin of the adult fingertip by said cannula tip. 3.Apparatus according to claim 1 wherein the tip of said cannula issufficiently blunt so that application of the cannula in a directionperpendicular to the normal intact human skin of the hands or arms witha force of about two pounds (889600 dynes) does not penetrate the skin,whereby the forces required to pass the cannula through said septa isless than the force required to cause the tip of said cannula topenetrate such normal intact human skin.
 4. Apparatus according to claim3 wherein said blunt cannula tip is rounded with a radius of curvatureof from 0.20 mm to about 1 mm, said first opening extending through aside of said cannula near the rounded tip but spaced therefrom. 5.Apparatus according to claim 3 wherein said blunt cannula tip issubstantially flat and circular, having a diameter of about 0.1 mm, saidfirst opening extending through the side of said cannula adjacent itsflat tip but spaced from said flat tip.
 6. Apparatus according to claim3 wherein the tip of said cannula is sufficiently blunt so thatapplication of the cannula in a direction perpendicular to normal intacthuman skin of the hands or arms with a force of about 5 pounds(2,224,000 dynes) does not penetrate the skin, whereby the forcerequired to pass the cannula through said septa is less than the forcerequired to cause the tip of said cannula to penetrate such normalintact human skin.
 7. Apparatus according to claim 1, wherein said bloodreceiving means includes means defining an interior chamber incommunication with said bore through said second opening and meanscoupled to said blood receiving means for displacing blood from saidinterior chamber through said second opening into said cannula bore andthrough said first opening into the container.
 8. Apparatus according toclaim 1 wherein said shroud has an open distal end and at least onedetent on said shroud located to engage the receiver device duringwithdrawal of the adapter from the receiver device to indicate when saidfirst opening is sealed at the penetrating portion of the receiverdevice.
 9. Apparatus according to claim 8, wherein said receiver devicecarries means engageable with said detent in response to partialwithdrawal of said cannula from said penetrating portions for precludingfurther withdrawal of said cannula from said penetrating portions andmaintaining said first bore sealed at the penetrating portions of thereceiver device.
 10. Apparatus according to claim 9, wherein saidreceptacle includes an interior chamber for receiving the blood.
 11. Asystem as in claim 1, wherein said maximum transverse internal dimensionof said shroud is at least 17.5 millimeters.
 12. A system as in claim 1,wherein said maximum transverse external dimensions of said centeringportion and of said end, and said maximum transverse internal dimensionof said shroud are all substantially the same so as to facilitatealignment of the cannula with each of said penetrating portion and saidseptum.
 13. A system as in claim 1, wherein each of said centeringportion, said adapter and said shroud are formed from a relatively rigidmaterial.
 14. A system as in claim 1, wherein said centering portion,said end of said discrete container and said shroud are each circular incross-section.
 15. A system as in claim 1, wherein said receptacle meanscomprises a syringe having a male connecting end and wherein said secondopening comprises a female connector for receiving said male end of saidsyringe.
 16. In combination with a blood aspiration system and adiscrete rigid vacuum filled container, an apparatus for transferring asample of blood from said aspiration system to said discrete container,comprising:an adapter including an axially extending cannula having adistal tip, said cannula having a bore with first and second openingsadjacent opposite ends of said bore and a shroud extending about saidcannula in transversely spaced relation thereto, said shroud extendingaxially beyond the distal tip of said cannula; a receiver device forminga part of said blood aspiration system and including a housing having aflow channel for communication with the human vasculature for flowingblood through the housing, said housing having a receiving portion forreceiving said cannula to locate the first opening of said cannula incommunication with said flow channel; means coupled to said adapter incommunication with said second opening for receiving blood drawn throughsaid bore; said discrete rigid, vacuum filled container having anopening at one end, and a septum occluding said opening; an externalconfiguration of the end of said discrete container and an externalconfiguration of said housing each being generally complimentary to aninternal configuration of said shroud, whereby (i) upon application ofsaid adapter to said receiver device, said shroud engages about saidhousing and centers said cannula for penetration of said receivingportion to locate said first opening in communication with said flowchannel and thereby to allow passage of blood from said flow channelthrough said bore into said blood receiving means, and, (ii) uponremoval of said adapter from said receiver device and upon applicationof said adapter to said container, said shroud engages about said end ofsaid discrete container and centers said cannula for penetration throughthe septum of said discrete container to locate said first opening incommunication with an interior of said discrete container thereby toallow blood to pass from said receiving means through said bore intosaid container.
 17. The combination of claim 16 wherein the externalconfiguration of the receiving portion of the housing and the end ofsaid discrete container are substantially identical one of the other.18. The combination of claim 16 wherein said shroud is generallycylindrical, coaxial with the axis of said cannula and has a generallycylindrical interior configuration concentric therewith, the externalconfiguration of said end of said discrete container and the externalconfiguration of said receiving portion of said housing each beingcylindrical and substantially identical one to the other.
 19. Thecombination according to claim 1 wherein said shroud is generallycylindrical, has an open distal end, and has an internal cylindricaldiameter and an axial extent sufficient to enable an adult fingertip tobe inserted within the shroud into contact with the tip of said cannula,said cannula tip being sufficiently blunt to inhibit penetration of theskin of the adult fingertip by said cannula tip.
 20. The combinationaccording to claim 16 wherein the tip of said cannula is sufficientlyblunt so that application of the cannula in a direction perpendicular tothe normal intact human skin of the hands or arms with a force of abouttwo pounds (889,600 dynes) does not penetrate the skin, whereby theforces required to pass the cannula through said septum is less than theforce required to cause the tip of said cannula to penetrate such normalintact human skin.
 21. The combination according to claim 20 whereinsaid blunt cannula tip is rounded with a radius of curvature of from0.20 mm to about 1 mm, said first opening extending through a side ofsaid cannula near the rounded tip but spaced therefrom.
 22. Thecombination according to claim 20 wherein said blunt cannula tip issubstantially flat and circular, having a diameter of about 0.1 mm, saidfirst opening extending through the side of said cannula adjacent itsflat tip but spaced from said flat tip.
 23. The combination according toclaim 16 wherein the tip of said cannula is sufficiently blunt so thatapplication of the cannula in a direction perpendicular to normal intacthuman skin of the hands or arms with a force of about 5 pounds(2,224,000 dynes) does not penetrate the skin, whereby the forcerequired to pass the cannula through said septum is less than the forcerequired to cause the tip of said cannula to penetrate such normalintact human skin.
 24. The combination according to claim 16 includingmeans carried in part by said receiver device responsive to at leastpartial removal of said adapter from said receiver device for precludingcommunication between said cannula bore and said flow channel and meanscarried by at least one of said cannula and said housing for indicatingwhen communication between said cannula and said flow channel isprecluded.
 25. The combination according to claim 24 wherein said bloodreceiving means includes an interior chamber and means coupled to saidblood receiving means for inducing a negative pressure within saidinterior chamber of said blood receiving means.
 26. The combinationaccording to claim 25 wherein said blood receiving means comprises asyringe and said negative pressure inducing means comprises a piston forsaid syringe in said interior chamber, said housing receiving portionbeing formed of elastomeric material for sealing about said firstopening of said cannula when said first opening is positioned withinsaid housing receiving portion during at least partial withdrawal ofsaid cannula from said housing receiving portion to precludecommunication between said cannula bore and said flow channel portion.27. The combination according to claim 16 wherein said blood receivingmeans includes an interior chamber, and means for displacing the bloodfrom said interior chamber through said second opening into said cannulabore and thorough said first opening into said container when saidadapter is applied to said container.
 28. The combination according toclaim 16 wherein said housing receiving portion including means defininga passage at an end portion of said housing in communication with saidflow channel, a septum occluding said passage, said shroud beingengageable about said housing end portion for centering said cannula onthe septum in said passage to facilitate penetration of the septum bysaid cannula.
 29. A method of transferring a sample of blood from a flowchannel in a receiver device of an aspiration system to a discretecontainer having a septum closing one end thereof, wherein the flowchannel is adapted for communication with a lumen of a blood vessel of apatient and the receiver device has a housing including a receivingportion for receiving a cannula, comprising the steps of:providing aflow of blood from the patient into the flow channel; providing anadapter including an axially extending cannula having a distal tip, saidcannula having a bore with first and second openings adjacent oppositeends of said bore and a shroud extending about said cannula intransversely spaced relation thereto, said shroud extending axiallybeyond the distal tip of said cannula; providing a receptacle incommunication with said second opening of said adapter; positivelycentering the cannula of the adapter relative to the receiving portionby engaging a shroud on the adapter about the receiving portion;penetrating the receiving portion with the centered cannula to place thecannula in communication with the blood in the flow channel; flowingblood from the flow channel through the cannula for reception in thereceptacle; removing the adapter from the receiver device; positivelycentering the cannula relative to the septum of the discrete containerby engaging the shroud of the adapter about the end of the discretecontainer; penetrating the septum of the discrete container with thecentered cannula to place the container in communication with the bloodin the receptacle; and flowing blood from the receptacle into thecontainer.
 30. The method according to claim 29 wherein the housingreceiving portion and container end are cylindrical and havesubstantially identical outside diameters and the further step offorming the inside diameter of said shroud to a dimension substantiallycomplementary to the dimension of the housing receiving portion and thecontainer end.
 31. The method according to claim 29 including the stepof providing a generally cylindrical shroud of a predetermined diameterand extending said cylindrical shroud axially to form an open distal endsuch that these diametrical and axial dimensions are sufficient toenable an adult fingertip to be inserted within the shroud into contactwith the tip of the cannula, and forming the tip sufficiently blunt toprevent penetration of the adult human fingertip by the cannula tip byapplication of the cannula tip against normal intact human skin of thehands and forearms with a force of about two pounds (889,600 dynes). 32.The method according to claim 29 including the steps of, prior toremoving the adapter from the receiver device, preventing the flow ofblood from the flow channel through the cannula, and, while the blood isprevented from flow from the flow channel through the cannula, reducingthe pressure of the blood in the receptacle so that the pressure of theblood within the receptacle is reduced.
 33. The method according toclaim 32 including the step of signaling with a sensory indication whenthe flow of blood from the flow channel through the cannula isprevented.
 34. A blood removal and transfer system including a bloodremoval assembly having a blood access means with a set internal flowvolume, the blood access means being for insertion in a blood vessel ofa patient, and a separate adapter for removing a sample of blood fromthe blood removal assembly and transferring the sample of blood to adiscrete container;(a) means defining a reservoir having a displacementvolume; (b) means for indicating when a displacement volume of fluid hasentered said reservoir; (c) a receiver device having a chamber forpermitting blood flow therein; (d) a first conduit for connecting theblood access means to said receiver device to establish flowcommunication between said receiver chamber and the blood access means;(e) a second conduit connecting said chamber of said receiver device andsaid reservoir means one to the other to establish flow communicationbetween said chamber and said reservoir means; (f) the adapter includingan axially extending cannula having a distal tip, said cannula having abore with first and second openings adjacent opposite ends of the bore,and a shroud extending about said cannula in transversely spacedrelation thereto, said shroud extending axially beyond the distal tip ofsaid cannula; (g) said receiver device having a receiving portion forreceiving said cannula to locate the first opening of said cannula inblood flow communication with the chamber of the receiver device so thatblood drawn into the receiver chamber and into the first conduit can bewithdrawn from the receiver chamber and the first conduit into theadapter; (h) means coupled to said adapter in communication with saidsecond opening of said cannula for receiving blood; (i) means forflowing a predesignated volume of blood from the blood vessel into theblood access means, said first conduit, the receiver chamber, and aportion of said second conduit whereby, upon entry of said predesignatedvolume of blood, substantially undiluted blood resides in the receiverchamber for removal through said adapter; said second conduit providinga capacitance function so that blood does not flow into said reservoirmeans; the predesignated volume of blood being equal to saiddisplacement volume of the reservoir and which is equal at least to theinternal flow volume of the blood access means; said first conduit andsaid receiver chamber; (j) the predesignated volume of blood being lessthan the internal flow volume of the blood access means, said firstconduit, the receiver chamber, and said second conduit; (k) a discreterigid, vacuum filled container having an opening at one end, and aseptum occluding said opening; (l) an external configuration of the endof said container and an external configuration of said cannulareceiving portion of said receiver device each being generallycomplementary to the internal configuration of said shroud whereby (i)upon application of said adapter to said receiver device, said shroudengages about said cannula receiving portion and centers said cannulafor penetration of said cannula receiving portion to locate said firstopening in communication with said receiver chamber, thereby tocommunicate blood from said receiver chamber through said bore into saidreceiving means, and, (ii) upon removal of said adapter from saidreceiver device and upon application of said adapter to said container,said shroud engages about said container end and centers said cannulafor penetration through the septum of said container to locate saidfirst opening in communication with said container, thereby tocommunicate blood from said receiving means through said bore into saidcontainer.
 35. The system according to claim 34 wherein the cannulareceiving portion, said container end and said shroud are all circularin configuration, the outside diameters of said receiving portion andsaid container end are substantially identical to one anther and saidshroud has an internal diameter sized to selectively receive either oneof said cannula receiving portion and said container end.
 36. The systemaccording to claim 35 wherein the outside diameter of said cannulareceiving portion is about 17.5 mm.
 37. The system according to claim 34including means carried in part by said receiver device responsive to atleast partial removal of said adapter from said receiver device forprecluding communication between said cannula bore and said receiverchamber and means carried by at least one of said cannula and saidhousing for indicating when communication between said cannula and saidreceiver chamber is precluded.
 38. Apparatus for use in transferring ablood sample taken from an aspiration system to a discrete rigid,hollow, evacuated container assembly, comprising:an upper adapterassembly including an axially extending cannula having a distal tip anda shroud extending about said cannula in transversely spaced relationthereto and extending axially beyond said distal tip; said systemincluding a port device having a flow channel for blood flowtherethrough and a receiving portion for receiving the cannula so thatthe distal tip is disposed within the flow channel; said discrete rigid,hollow, evacuated container assembly having a closed penetrable firstend; said first end of said discrete container and said port device eachhaving an external configuration that is generally complementary to aninternal configuration of said shroud, defining means for guiding saidcannula along an axis of said penetrable first end and an axis of saidreceiving portion, respectively, to substantially prevent said cannulafrom canting or inclining upon application of a force necessary for thecannula to penetrate the same, to substantially prevent said cannulafrom being broken or fractured upon such penetration, whereby (i) uponapplication of said adapter assembly to said port device, said shroudreceives the external configuration of said port device to guide saiddistal tip through the receiving portion into said flow channel therebyto allow passage of blood from said flow channel into said cannula and,(ii) upon removal of said adapter assembly from said port device andupon application of said adapter assembly to said first end, the shroudreceives the external configuration of said first end and guides saidcannula during penetration thereof through said first end to locate saiddistal tip within the hollow interior of said discrete containerassembly.
 39. An apparatus as in claim 38, wherein said port deviceincludes a housing having said receiving portion, said housing havingsaid generally complementary external configuration.
 40. An apparatus asin claim 38, wherein a septum closes said first end.
 41. An apparatus asin claim 40, wherein a septum has said generally complementary externalconfiguration.
 42. An apparatus as in claim 38, wherein said adapterassembly further includes a reservoir in flow communication with saidcannula to receive the sample of blood.
 43. An apparatus as in claim 38,wherein said shroud has a generally cylindrical internal configurationand at least a portion of first end and at least a portion of said portdevice have a generally circular cross-section for being received bysaid shroud.
 44. An apparatus as in claim 38, wherein said cannula isformed from polycarbonate.
 45. An apparatus as in claim 38, wherein thedistal tip of said cannula is sufficiently blunt so that application ofthe cannula in a direction perpendicular to the normal intact human skinof the hands or arms with a force of about two pounds (889,600 dynes)does not penetrate the skin, whereby a force required to pass thecannula through said receiving portion is less than a force required tocause the tip of said cannula to penetrate such normal intact humanskin.